Data are transmitted using data networks, such as networks in the synchronous digital hierarchy, SDH for short, or synchronous optical networks, SONET for short. These networks transmit data using virtual containers, VC for short. For this purpose, the data are inserted into virtual containers at the transmission end. The virtual containers essentially comprise a portion for useful data and a portion for overhead data, which are used for controlling, managing, administering, etc. the network or the containers. Virtual containers can be connected to one another to form concatenated virtual containers or linked virtual containers. These are also called virtually linked signal elements. A plurality of such virtual containers or concatenated virtual containers can be combined to form a virtual concatenated group, for example using the Link Capacity Adjustment Scheme, LCAS for short, on the basis of the ITU-T G.7042 standard. In this context, different concatenated virtual containers from a virtual concatenated group can be transmitted via different transmission sections or routes, paths or links in the data network. The (useful) data are inserted and removed in network elements in the data network, which are in turn connected to one another by various transmission paths.
The LCAS method can be used to insert data into a virtual concatenated group. The data in a virtual concatenated group are transmitted using (concatenated) virtual containers, these being transmitted from the source via various transmission sections to a sink/a destination. This is referred to as what is known as diverse routing. By way of example, a first group of virtual containers in a virtual concatenated group is transmitted via a first transmission link and a second group of containers in the virtual concatenated group is transmitted via a second transmission link. If the first transmission link fails in the event of a fault, LCAS is used to reduce the bandwidth of the virtual concatenated group by the quota of the portions routed via the failed link. That is to say that the connection is maintained but the bandwidth is reduced.
In the case of services which require or guarantee a stable bandwidth, this practice can result in unacceptable losses of quality.